Circuit-interrupter.



K.C.RANDALL CIRCUET INTERRUPTER. 7 APPLICATION FILED Aue.2.;912;

VEwYOR ATTQRNEY Patented Apr. 30,. 1918 Circuit-Interrupters,

' is a View, mainly in d lt ddtdhlti KAItL C. BATDTZDRCLL, OF EDG EWOOD PARK, EENNSYLVANIA, ASSIGNGR 3T0 WE TING-e HOUSE ELEGTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYL VANIA.

CIRCUIT-INTERRUPTIJR.

specification of Letters Yatent.

racemes Apr. so. rare.

Application filed August 2, 1913. Serial No. 782,541

To all to hom it may concern:

Be it known that citizen'of the United States, and a reel of Edgewood Park, in the county of tile gheny and State of Pennsylvania, have invented a new and useful improvement in of which the follow- .l, KARL G. RANDALL, a dent int; is a specification.

My invention relates to circuit interrupters and particularly to knife-blade switches of the quick-break type.

T he object oi my invention is to provide a knife-blade switch of the quick-break type,

the quick-break attachment of which shall be of such construction and have such coo Jerative relation with the other parts 0 switchthat injury to thecotiperating contact portions by arcing and pitting shall be prevented.

A further object of my invention is to provide a knife-blade switch, the jaw contact formed as to insure prompt. rupture of such arcs as may be pro duced when the switch is opened.

Knife blade switches which have hereto' fore been provided with quiclnbrcak attachments, have been reasonably efiectire within certain limits. as regards the amount and character of the energy interrupted, but, be-

yond certain well defined limits the arcs produced-at the instant of separation between the quick-break attachment and the contact jaws have burned the contact surfaces to such an cs1 tent as to materially impair usefulness of the switches.

My present invention is intended to provide a means for use in connection with circuits carrying relatively large amounts cit energy and to provide for the final interruption of the circuit. between portions of the contact members of the switch which are not in engagement under any condition.

In the accompanying drawing, Figure l side elevation, but pan tially in section, of a switch embodying my invention, and Fig. 2 is a detail View of parts of the contact members shown in Fig. 1. 4

The .ain contact blade 1 of the switch shown in the drawing is pivotally supoorted by one of the terminals 2 and is more. is on such pivotal support into and out the injuriously pitted or gagement with the jaws 3 of the other switch terminal. The members 2 and 3 are mounted upon an insulating base or panel 4: and have cylindrical screw-threaded projections which extend through holes in the part 4. and are provided with terminal connecting devices 5 at the rear of the anel in accord ance with the usual practice. 'l he switch blade 1 is provided with an operating hen dle 6 and with a quick break attachment device 7, the ends 8 and 9 of which are bent laterally in opposite directions but in the same 'plane. lhe laterally bent end 9 of the attachment device 7 is pivotally attached to the blade member 1 at 10., and the outer edge of its body portion is normally held in engagement with the inner edge oi the blade 1 by means of a spring 11. The laterally bent free end 8 of the ihen'iber 7 is rounded to serve as the terminal at which the final rupture of any are which may be formed. by bpening the switch occurs.

The main body portions of the jaw terminal 3 are substantiallyparallel to make efiecti've contact with the sides oi-the blade l, but the outer ends 12 of such jaw members diver e from each other to form a space 13 oiisu' stantially ti-shape. The portion 8 of the member 7 is adapted to remain out of en gugement with the outer ends 12 of the jaw members under all conditions.

Assuming that the switch is closed and. the circuit in which it is connected is carrying; ciilrront, the switch blade 1 will be moved outwardly by means of the handle 6 and. on account of the friction between the mcnber 7 and the jaw surfaces, the spring ll. will yield suliiciently to permit the blade 1 to become separated from the jaws before the member 7 is unseated. When the tension upon the spring l-ll. becomes suliicient to effect withdrawal of the member l, the latter will spring from its seat in the jaws with a quick snap action and the final rupture of such are as may be termed will be at a point on the portion 8 of the member 7 that is not in contact engagement with the jaws under any condition. Fur thermore, the rllivergence oi" the ends oilthe jaw members tends to spread such arcs as may be formed and interrupt the same more quickly than would otherwise he the case.

l e/liner variations as to the site, shape and its non-engaging portions of the contact jaws to receive the are that is drawn when the device is opened.

2. A knife-blade switch comprising a main knife-blade member, contact jaws having no1iengaging portions, and an auxiliary quick-tweak knifeblade member hav ing a portion. that is adapted to remain out of engagement with the contact jaws under all conditions and to receive the arc from the non-engaging portions of the contact; jaws when the switch is opened.

Aswiteh comprising a stationary contact member having a non-engaging arcing portion and a movable contact member having a non-engaging portion adapted to cooperate with the non.-engaging portion of the stationary contact member to receive the final. break of the are that is drawn when the switch is opened.

a. A switch comprising a knife-blade member having a non-engaging portion and contact jaws therefor having non-engaging portions that cooperate with the non-engaging portion of the knife-blade member to receive the are that is drawn when. the switch is opened.

:1 A switch comprising a stationary eontact member having a non-engaging arcextingnishing portion and a movable eontaet member having a portion for cooperating only with the non-engaging arc-extingnishingr portion to receive the are that is drawn when the' switch is opened.

0. A switch comprising contact jaws having non-engaging diverging outer ends and a knife-blade member havin a lateral projection at its outer end that is adapted to remain out of engagement with the contact jaws and to cooperate with the diverging outer ends thercol to receive the are that is drawn when theswitch is opened.

' 7. A switch comprising contact having non-engaging diverging outer and a knife-blade member therefor a laterally extending outer end that is adapted to pass between, but out of engt-igo ment with the diverging outer ends of the jaws to receive the are that is drawn when the switch is opened.

A switch comprising a stationary contact member having a non-engaging portion and a movable contact member having a non-engaging portion to cooperate with the non-engaging portion of the stationary contact member to receive the are that is drawn when the switch. is opened.

In testimony whereof I have hereunto subscribed my name this 20th day of July, 1913.

jaws ends having Cnas. MoL. Moss,' I5. B. I-Imns. 

